This invention relates to particle impact treatment of fibers and fabric in order to enhance the dyeability characteristics of fabrics or fibers that are difficult and sometimes impossible to dye such as aromatic polyamides (polyaramids).
Polyaramids have been found to be well-suited for applications in areas exposed to transient or continuous high temperatures and for personal protection such as in ballistic vests and in cut resistant gloves. In areas where high temperature resistance and dyeability are important, fabrics constructed of relatively low modulus aramid fibers such as those of poly(meta-phenylene isophthalamide) are used. In areas where high strength is of primary importance, as in ballistic protection, fabrics of high modulus aramid fibers such as poly(para-phenylene terephthalamide) are used. Fabrics constructed of such high modulus aromatic polyamide fibers, hereinafter known as HM-aramid fibers, are extremely difficult to dye, while lower modulus aramid fibers, hereafter known as LM-aramid fibers can be dyed to dark shades only by use of suitable swelling agents or carriers. Therefore, it would be highly desirable to modify the HM-aramid fibers to produce a dyeable fabric with minimal degradation to physical properties. Likewise, it would be desirable to modify LM-aramid fibers to produce a fabric dyeable without recourse to environmentally problematic chemical agents.
The present invention solves the above problems in a manner not disclosed in the known prior art.